Micrographics is a general term employed to denote the creation or use of information communication or storage media containing images too small to be read without magnification. The images generally are reduced images of printed or other graphics, graphical design and the like for storage in the printed form and enlargement for printing or projection retrieval.
Conventionally, the art of micrographics employs high speed, fine grain, expensive film in view of the requirements of the substantial reduction of the size of the image and the substantial enlargement required for viewing. These films generally required expensive chemicals and processing, needing special handling since they are relatively bulky, light sensitive and difficult to store. Additionally, these films do not provide for re-exposure to add information to already prepared past images.
Xerographic processors have been suggested but for many reasons, including low gain, long processing times, complex equipment of substantial bulk, poor storability, low resolution and low throughput capability. In many instances, available apparatus was not suitable for operation in an office environment under normal ambient lighting. Operation at a high noise level, solvent emission, inability to meet or exceed the applicable standards for conventional film, all restricted the use of xerographic processes and equipment for micrographic processing, such as for production of microfilm.
Cited U.S. Pat. No. 4,521,097 provided a method and apparatus for making an image carrying transparency having a reduced image such as suitable for micrographic applications such as microfilm. In said patent there was described a method for producing an image-carrying receptor of an original image which eliminated many of the above mentioned problems encountered with the use of silver halide film and/or the prior electrophotographic methods of imaging on a receptor substrate. There was provided a light excluding housing, a stepwise translatable carriage disposed within the housing and plural operational stations disposed spaced along the path of the carriage and each providing one of the operational steps in the electrophotographic process. The method consisted of the steps of providing a planar electrophotographic member having a photoconductive surface facing outwardly, applying an electrostatic uniform charge to the photoconductive surface, projecting a light pattern representative of the original information onto the charged surface forming a latent electrostatic image on said charged photoconductive surface, rendering the latent charge image visible by toning with a liquid toner, drying the resulting photoconductive surface and the toner image thereon, transfering the toned image to a transfer medium using locally applied heat and pressure, cleaning the residual photoconductive surface and discharging said surface thereafter. The functional stations were housed in a light-excluding enclosure. The electrophotographic members were mounted platens carried by a carriage and presented to the respective stations successively. The apparatus described in said referenced patent particularly was intended to provide images on receptor means premounted in a rectangular aperture in a standard sized micrographics aperture card and did not produce microfilm in strips or the like film. The receptor employed in this method comprised an overcoated non-light sensitive polyester substrate carrying a coating of heat softenable resin described in U.S. Pat. No. 4,529,650 referenced above.
The method and apparatus disclosed in said referenced patent provided an efficient processor for forming permanent, high resolution micrographic image carrying transparencies. However, such apparatus was bulky, was not suitable for providing images upon strip and/or roll film, was limited in the speed of operation and throughput, required considerable space, was not adapted for use in an office environment and was expensive to construct, to assemble and to maintain.
A growing need has arisen to provide a microfilm camera/processor which would overcome the disadvantages of prior attempts to utilize the method proposed in said referenced patent for forming micrographic images on strip and/or roll microfilm, to provide a camera/processor which would enable immediate access to strip and/or roll transfer medium rapidly and immediately available for use, i.e. for projection or duplication, for example. Further, the long sought camera/processor should be able to combine the reduction capability with the functional steps of said disclosed method, which is able to provide either batch or continuous production of microfilm for immediate use, which is capable of providing instantaneous access to the produced microfilm, which is versatile as to size of the originals capable of being treated, which can be automated and all with using the method first disclosed in the referenced patent except for selected features indigenious to the herein invention.